ChemFOnt: Showing chemical card for 3-Methylindole (CFc000000354)

Record Information

Version

1.0

Creation Date

2022-08-28 10:25:12 UTC

Update Date

2022-09-13 18:44:43 UTC

Chemfont ID

CFc000000354

Molecule Identification

Common Name

3-Methylindole

Definition

3-Methylindole, or skatole, belongs to the indole family and has a methyl substituent in position 3 of the indole ring. It occurs naturally in feces, beets, and coal tar, and has a strong fecal odor. Its name is derived from skato, the Greek word for dung. It exists as a white crystalline or fine powder solid, and it browns upon aging. 3-Methylindole is produced from tryptophan in the mammalian digestive tract where tryptophan is converted to indoleacetic acid, which decarboxylates to give the methylindole. These reactions are largely driven by the microbiota in the digestive tract. 3-Methylindole is soluble in alcohol and benzene and it gives violet color in potassium ferrocyanide (K4Fe(CN)6.3H2O) mixed with sulfuric acid (H2SO4). Skatole has a double ring system which displays aromaticity that comes from the lone pair electrons on the nitrogen. It is continuous (all atoms in the ring are sp2 hybridized), planar, and follows the 4n+2 rule because it has 10 pi electrons. In a 1994 report released by five top cigarette companies, skatole was listed as one of the 599 additives to cigarettes. This is because in low concentrations skatole has a flowery smell and is found in several flowers and essential oils, including those of orange blossoms, jasmine, and Ziziphus mauritiana. As a result, skatole/3-methylindole is used as a fragrance and fixative in many perfumes and as a general aroma compound for other applications. 3-Methylindole has been found to be a bacterial metabolite of members of the Clostridium (PMID: 18223109 ) and Lactobacillus (PMID: 16345702 ) families. Skatole functions as an insect attractant and is one of many compounds that are attractive to males of various species of orchid bees, which apparently gather the chemical to synthesize pheromones; it is commonly used as bait for these bees for study (PMID: 12647866 ). It is also known for being an attractant for the Tasmanian grass grub beetle (Aphodius tasmaniae). Skatole has also been shown to be an attractant to gravid mosquitoes in both field and laboratory conditions (PMID: 24242053 ).

Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
3-Methyl-4,5-benzopyrrole	ChEBI
beta-Methylindole	ChEBI
Skatol	ChEBI
b-Methylindole	Generator
Β-methylindole	Generator
3-Methyl-1H-indole	HMDB
3-MI	HMDB
Scatole	HMDB
Skatole	HMDB
3 Methylindole	HMDB
3-Methylindole	ChEBI

Chemical Formula

C₉H₉N

Average Molecular Weight

131.1745

Monoisotopic Molecular Weight

131.073499293

IUPAC Name

3-methyl-1H-indole

Traditional Name

scatole

CAS Registry Number

83-34-1

SMILES

CC1=CNC2=CC=CC=C12

InChI Identifier

InChI=1S/C9H9N/c1-7-6-10-9-5-3-2-4-8(7)9/h2-6,10H,1H3

InChI Key

ZFRKQXVRDFCRJG-UHFFFAOYSA-N

Chemical Taxonomy

Description

Belongs to the class of organic compounds known as 3-methylindoles. These are aromatic heterocyclic compounds that contain an indole moiety substituted at the 3-position with a methyl group.

Kingdom

Organic compounds

Super Class

Organoheterocyclic compounds

Class

Indoles and derivatives

Sub Class

Indoles

Direct Parent

3-methylindoles

Alternative Parents

Substituents

3-methylindole
Benzenoid
Substituted pyrrole
Heteroaromatic compound
Pyrrole
Azacycle
Organic nitrogen compound
Organopnictogen compound
Hydrocarbon derivative
Organonitrogen compound
Aromatic heteropolycyclic compound

Molecular Framework

Aromatic heteropolycyclic compounds

External Descriptors

methylindole (CHEBI:9171 )
a small molecule (SKATOLE )

Functional Ontology

Non-excretory biofluid

Biofluid or Excreta

Saliva (PMID: 24421258)

Excreta

Biofluid or Excreta

Feces (PMID: 17314143)

Cellular substructure

Membrane (HMDB: HMDB0000466)

Source

Endogenous

Endogenous (HMDB: HMDB0000466)

Red beetroot (FooDB: FOOD00264)

Cabbage

Cauliflower (FooDB: FOOD00031)

Leaf vegetable

Common beet (FooDB: FOOD00025)

Process

Not Available

Role

Not Available

Physical Properties

Predicted Properties

Property	Value	Source
Water Solubility	3.09 g/L	ALOGPS
logP	2.58	ALOGPS
logP	2.59	ChemAxon
logS	-1.6	ALOGPS
pKa (Strongest Acidic)	17.48	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	0	ChemAxon
Hydrogen Donor Count	1	ChemAxon
Polar Surface Area	15.79 Å²	ChemAxon
Rotatable Bond Count	0	ChemAxon
Refractivity	42.19 m³·mol⁻¹	ChemAxon
Polarizability	14.95 Å³	ChemAxon
Number of Rings	2	ChemAxon
Bioavailability	Yes	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	No	ChemAxon
Veber's Rule	Yes	ChemAxon
MDDR-like Rule	No	ChemAxon